St. Mary's is a city located in Alaska. With a 2020 population of 575, it is the 50th largest city in Alaska and the 12725th largest city in the United States. St. Mary's is currently growing at a rate of 0.70% annually and its population has increased by 13.41% since the most recent census, which recorded a population of 507 in 2010. Spanning over 52 miles, St. Mary's has a population density of 13 people per square mile.
The average household income in St. Mary's is $51,869 with a poverty rate of 31.25%. The median rental costs in recent years comes to $850 per month, and the median house value is $105,000. The median age in St. Mary's is 24.6 years, 24 years for males, and 24.7 years for females. For every 100 females there are 116.2 males.